The invention relates to an apparatus for transferring objects lying flat, especially folded boxes of the kind known from European Patent Disclosure EP 0 434 961 A1. The known apparatus has a star-shaped, continuously driven rotor with a plurality of suction heads disposed in staggered fashion on the rotor. When a folded box is transferred from a folded box magazine to between the drivers of a continuously driven conveyor chain, the suction head that holds the folded box follows an intrinsically closed cycloidal path, and the folded box, lying flat, is erected between a folded box magazine and the conveyor chain.
A disadvantage of this known apparatus is that because of the cycloidal path, the suction cup on pulling a folded box from the folded box magazine does not execute a solely vertical motion, and on transferring the folded box to between the drivers of the conveyor chain, the box does not execute a forward or horizontal motion that is adapted to the speed of the conveyor chain. As a result of both these factors, the disposition and adaptation of the rotor, folded box magazine and conveyor chain requires relatively major effort, especially for folded boxes whose format and quality of material are critical, if uninterrupted operation of the apparatus is to be possible.
If one seeks to increase the output of the known apparatus, this can be done by increasing the number of suction heads disposed on the rotor, or by increasing the rotary speed (rpm) of the rotor. Increasing the number of suction heads on the rotor entails increased engineering effort and expense, on the one hand, and on the other, is subject to space limitations because of the disposition between the folded box magazine and the conveyor chain. Increasing the rotor rpm is problematic, too, because the load and the forces on the folded box in the erection process can then become excessive.
The apparatus according to the invention for transferring objects lying flat, especially folded boxes, as defined herein has the advantage over the prior art that the course of motion of the suction head can be adapted optimally to the particular function required. This means that a folded box blank is being pulled out of the folded box magazine, lateral motion of the suction head relative to the folded box magazine is absent, or virtually absent, as long as the folded box blank is located in the region of the folded box magazine. Furthermore, the transfer of the erected boxes to between the drivers of the conveyor chain is done at a horizontal speed that is adapted to the conveyor chain.
In addition, with the apparatus of the invention, an especially high output can be attained. This is because along the first segment, in which the first folded box lying flat is erected, the folding box blank is conveyed at a speed it can tolerate, and thus the forces acting on the box in the erection process are limited. By comparison, in the second segment, in which the suction head moves from the conveyor chain toward the folded box magazine in order to take up the next folded box blank, the speed of the suction head can be increased. The overall result, compared with known apparatuses, is a higher, variously variable rotary speed of the suction head.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings.